Accelerators of vulcanization



Patented Sept. 18, 1945 UNITED STATES PATENT OFFICE ACCELERATORS OF VULCANIZATION Albert F. Hardman, Akron, Ohio, assignor to Wingfoot Corporation, Akron, Ohio, a corporation of Delaware No Drawing. Application February 26, 1943, Serial No. 477,263

1 Claim. (Cl. 260455) This invention relates to the vulcanization of washed with alcohol. After drying, the product rubber and more particularly to the provision and weighed 35 grams and melted with decomposition use of a novel and specific accelerator. at 157 C. The product is believed to conform to According to the present invention, B-naph the following structural formula:

thol, benzaldehyde and dimethylamine are re- 5 acted to form 1-(alpha-dimethyl-aminobenzyl) naphthol-Z. This compound is then further reacted with a mol of carbon bisulfide to produce H-SCN(CH3)2 an addition product in which the two materials combine in equimolecular proportions. H The preparation of the accelerator comp u Analysis showed a sulfur content of 18.03% and 1S Illustrated by the folmwmg examples: a nitrogen content of 3.60%. The theoretical sulfur and nitrogen contents based on the structural formula shown are 18.1% and 3.96%, re- A mixture of 72 grams of fi-naphthol, 90 grams pective1y Of a aqueous solution of dimethy am ne, 53 The product of Example 2 was compounded grams of freshly distilled aldehyde and 100 into rubber as an accelerator according to folcc. of ethyl alcohol was allowed to stand at room lowing Formula, A d samples were cured and temperature of 2 days. Crystals began to sepat t in the usual manner rate after about 2 or 3 hours. The crystals were Example 1 filtered OE and washed with alcohol. The yield Formula A was 107 grams. The product melted at 156-158 Parts by weighg C. and corresponds to the structural formula sheet rubber Zmo oxide 5.0 Sulfur 3.0 Accelerator 0.5

H-N(CHS)1 An excellent cure was obtained in minutes at 240 F. with no tendency to scorch. The ulti- H mate tensile strength was 190 kg./sq. cm., the Example 2 30 ultimate elongation was 755% and the modulus at 500% elongation was 32 kg./sq. cm. e ygrams of p ylam The method of treating rubber and the rubber nobenzyl) naphthol-2 (the product of Example product obtained by the practice of this inven- 1), 10 grams of carbon bisulfide and 100 cc. of tion are claimed in co-pending application Serial ethyl alcohol were mixed and the mixture was No. 576,371, filed February 5, 1945.

refluxed for '7 or 8 hours. The white crystals 1 claim;

originally present did not dissolve immediately in As a new compound, the addition product of h boiling solvent but slowly chan e in appearequimolecular proportions of carbon bisulfide and ance. The mixture was allowed to stand overl-(a-dimethylaminobenzyl) naphthol-Z.

night and the crystals were then filtered oil. and ALBERT F. HARDMAN. 

